In January 2009, the engine then known as SquirrelFish Extreme (SFX) was enabled for Mac OS X on x86-64 architectures as it passes all tests on that platform by Apple Inc. Released June 30, 2009, Firefox 3.5 includes the optimization technique that offered "performance improvements ranging between 20 and 40 times faster" compared to Firefox 3 in some cases.
A dialect and an implementation are distinct: a dialect of a language is a significant variant of that language, while an implementation of a language (or dialect) executes a program written in that language (or dialect).
|Application||Dialect and latest version||ECMAScript edition|
and JScript extensions
|ECMA-262, edition 5.1|